luminosity

[shatabdo.kal]

Source: Peterson
The time it takes for a star to change its brightness is directly related to the luminosity of it.
a. the luminosity of it
b. the luminosity of its brightness
c. the luminosity of a star
d. luminosity of it
e. its luminosity

[ujjavalgupta]

To me, Option E appears best.
Its refers to "Star" Singular...
Whats the Official Ans ?

[shatabdo.kal]

I think there is ambiguity in it

[pawan_chitturu]

This is a GMAT question related to Possesive Poison

The time it takes for a star to change its brightness is directly related to the luminosity of it.
a. the luminosity of it
b. the luminosity of its brightness
c. the luminosity of a star
d. luminosity of it
e. its luminosity

Subject and object pronouns may only refer back to subject and object nouns. it will be only accurate if it referred back to a star.

Even though it is obvious that it refers to a star, the sentence must be changed in order for it to be gramatically correct on the GMAT. We can fix the sentence by keeping its and eliminating it

Therefore answer will be option c

Experts can explain in detail

[thoppae.saravanan]

Its brightness refers to star brightness. Its luminosity refers to star luminosity. There is no ambiguity in this pronoun reference. So will go for option E. What is OA btw?

[shatabdo.kal]

Can any of the experts be kind enough to tell me why E is better than A?

[ujjavalgupta]

Hope this may help..
The time it takes for a star to change its brightness is directly related to its luminosity .

[ugenderr]

I think "its" is fine here so answer can be either B or E.

I pick E since it is parallel to "its brightness". And in B, brightness and luminosity are redundant?

My pick is E.

[chunyang.yu]

The time it takes for a star to change its brightness is directly related to the luminosity of it.

I go with E.
I think the it in the sentence will first refer to brightness, and then it also can refer to a star, so it seems ambiguity.