Meteor shower!

[gmat_perfect]

Meteor showers and individual streaks of light that flash across the sky every night are generated when tiny flecks of celestial detritus, often no larger than grains of sand or of pebbles, burn up speeding through the atmosphere.

(A) grains of sand or of pebbles, burn up speeding
(B) grains of sand or pebbles, burn up while speeding
(C) grains of sand or pebbles, which burn up while speeding
(D) a grain of sand or pebble, which burns up as it speeds
(E) a grain of sand or a pebble, burns up when it speeds

How I have reached:

The skeleton of the sentence:

when tiny flecks of celestial detritus, often no larger than grains of sand or of pebbles, burn up speeding through the atmosphere.

when tiny flecks of celestial detritus burn up speeding through the atmosphere.

From here, it is seen that it is the flecks that burn up.

So, CDE can be easily eliminated.

Though I have selected B, I have a doubt why A is wrong.

Would any one clarify?

Thanks.

[uwhusky]

Couple things with A that's different than B:

grains of sands or grains of pebbles. In English, we say grains of sands/salts, but we don't say grains of pebbles.

Another is that "speeding" should be a verb conjoined with "burn up", but in A, it is incorrectly structured.

[reply2spg]

A is not good because tiny flecks because they speed. so you need while to show that speeding and burning happen at the same time. That is why I choose B

Meteor showers and individual streaks of light that flash across the sky every night are generated when tiny flecks of celestial detritus, often no larger than grains of sand or of pebbles, burn up speeding through the atmosphere.

(A) grains of sand or of pebbles, burn up speeding
(B) grains of sand or pebbles, burn up while speeding
(C) grains of sand or pebbles, which burn up while speeding
(D) a grain of sand or pebble, which burns up as it speeds
(E) a grain of sand or a pebble, burns up when it speeds

How I have reached:

The skeleton of the sentence:

when tiny flecks of celestial detritus, often no larger than grains of sand or of pebbles, burn up speeding through the atmosphere.

when tiny flecks of celestial detritus burn up speeding through the atmosphere.

From here, it is seen that it is the flecks that burn up.

So, CDE can be easily eliminated.

Though I have selected B, I have a doubt why A is wrong.

Would any one clarify?

Thanks.