crick wrote:+1 for C.

I eliminated E because i didn't like "indications". I felt "indicators" was more appropriate .

Crick

mukgera wrote: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.

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

we are trying to point out one reason out of several other reasons so 'are' is wrong here.

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

Again same error as A. so eliminated this one as well.

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

Clear and concise - contender.

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

Highlighted part is not clear. In my opinion if it would have been like 'Indications of sunspot cycles on earth' then it would be more clear.

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

Same as D

So only C remains.

OA is C. Mine was E. Can someone explain..?