"Rate of growth" is singular. So lets eliminate A & B

The sentence construct in D is very odd and use of passive voice in E... which leaves us with C.

OA please?

Agree with sankruth. Any more input friends ...

A. On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow
awkward construction

B. On Earth, among the surest indications of sunspot cycles are, it is believed, the rate of tree growth
it refernce unclear

C. On Earth, the rate at which trees grow is believed to be among the surest indications of sunspot cycles
among does not seem correct requires teh superlative

D. Among the surest indications on Earth of sunspot cycles, believed to be the tree growth rate


E. Among the surest indications on Earth of sunspot cycles is believed to be the rate at which trees grow


What is believed to be indicating the sunspots ...the rate of tree growth Hence E is best

This is a misplaced modifier problem

On Earth ? what

the only entity that can be logically modified bu this phrase is "rate of tree growth"

A. On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow

Misplaced Modifier -- Incorrect
B. On Earth, among the surest indications of sunspot cycles are, it is believed, the rate of tree growth

Misplaced Modifier -- Incorrect
C. On Earth, the rate at which trees grow is believed to be among the surest indications of sunspot cycles

Correct use of modifier however the clause "as seen in the rings visible in the cross sections of their trunks" would not qualify sunspot cycles

D. Among the surest indications on Earth of sunspot cycles, believed to be the tree growth rate

Misplaced Modifier(Among the surest indications on Earth of sunspot cycles does not qualify believed)- Incorrect

E. Among the surest indications on Earth of sunspot cycles is believed to be the rate at which trees grow

(proper use of modifiers)

Correct

The answer is C.

A -- 'are' is plural but references "the rate at which trees grow, which is singular" INCORRECT

B -- same as A

C -- no grammar error. It seems like the 'among' is throwing people off, but it is okay to put that there to modify "surest indicators". Because there is more than one indicator that is considered sure, 'among' means that the rate of tree growth is only one of them, neither more or less sure than any of the others referenced. CORRECT

D -- passive, nonsensical

E -- same as D. Both D and E are practically out of order and the meaning of the sentence is almost completely lost in the awkward construction.

Hi Danielle,
Actually I was also inclined towards C, but I left it for one reason:-

OS: On Earth, among the surest indications of sunspot cycles are believed to be the rate that trees grow, as seen in the rings visible in the cross sections of their trunks.

the highlighted clause should modify trees (trees have trunks)

in option C we have

On Earth, the rate at which trees grow is believed to be among the surest indications of sunspot cycles , as seen in the rings visible in the cross sections of their trunks.

Here the same clause would not modify sunspot cycles

however in option E we have

Among the surest indications on Earth of sunspot cycles is believed to be the rate at which trees grow,as seen in the rings visible in the cross sections of their trunks

here again the clause modifies trees

Pls suggest if you think otherwise, Thanks

Seekmba, you're right. I must recant my previous breakdown, as I did not read carefully enough to spot the modifier error.

I'd love to say that I was just testing ya'll, but I cannot tell a lie... you guys are just getting damn good at this! Keep up the good work! 8)

Thanks for your comments Danielle, technically I must say that it can be called "Evolution" , however you are the one who is driving it, Thanks for your support.

Go Darwin! Thanks for the cool comments also. Here's to evolution!

@Danielle @ seekmba
Gud piece of explanation...

I picked up C