MahmoudFawzy
Cashmere prices rose dramatically Tuesday, reaching their highest level since the recession, after last week’s disastrous storms in Mongolia led to fears that there could be a threat to the world’s main source of cashmere goats when at a time with their numbers are already low.
A) that there could be a threat to the world’s main source of cashmere goats when at a time with their numbers are
B) that the world’s main source of cashmere goats could be threatened at a time such as when their numbers are
C) that the world’s main source of cashmere goats could be threatened at a time when their numbers are
D) of the world’s main source of cashmere goats perhaps being threatened at a time with their numbers
E) of perhaps threatening the world’s main source of cashmere goats at a time that their numbers were
Source: Ready4GMAT
Split 1 - When at a time \ at a time when.
Split 2 - that \ of
Split 3 - there could be a threat \ could be threatened
At a time is when is the correct modifier.
So A, D and E are out
Between B and C, B uses such as which is not required as time is not an example here. The meaning is that the Cashmere goats are threatened at a time when their their numbers are already low.
Hence C is the answer