vivek123
I think "which" is needed.
Here is my reasoning,
Bihar is India’s poorest state,
with an annual per capita income of $111,
lower than in the most impoverished countries of the world.
If I read the sentence carefully, "lower than..." seems to modify first sentence & not the "orange" color sentence,
which is provided as additional information about Bihar.
But we need to refer to noun in this additional information, hence we need "which"!
What do you think?
(Bhaiyyo, I hate Lalu for making Bihar poorest state but because of him Bihar reached SC section of GMAT

)
dont know if I am dragging this far to long
but consider this
The McClaren F-150 is the most sought after high performance vehicle in the world, with a top speed of over 250 miles per hour, higher than any other non-racing equipped automobile available to the public.
(A) higher than
(B) and is higher than
(C) which is higher than those of
(D) which is higher than that of
(E) higher than that of
D or E
I would rule out D because of unclear referent.. referent should be 'top speed' and adjacent to and before ‘which’
E is POE
In Bihar question
177. Bihar is India’s poorest state, with an annual per capita income of $111, lower than in the most impoverished countries of the world.
(A) lower than in
(B) lower than that of
(C) and lower than that of
(D) which is lower than in
(E) which is lower than it is in
I would look for || ism ‘per capita income of’ || with ‘lower than that of’
Again, ‘which’ does not have a clear referent … it should modify ‘annual per capita’ and follow proximity rule.
Can someone please confirm ?