A’s and B’s Salaries are in the proportion of 4 : 3 respectively. What is A’s salary ?
I. B’s salary is 75% that of A’s salary.
I. B’s salary is Rs. 4,500.

Suppose A's salary is 4x and B's salary is 3x.

Statement 1: B's salary is 75% of that of A's salary. This statement is the same as the original statement since 75% equals 3/4. So, we dont get any valuable iformation from this statement.

Statement 2: B's salary is 4500 Rs.

Combining with original statement, 3x = 4500

Therefore, x = 1500

And 4x = 6000.

Hence, we get A's salary as Rs 6000. 

So, the second statement is sufficient to get A's salary. Hence Option (B).