To find the smallest number by which 2048 must be divided so that the quotient is a perfect square, we have to find the prime factors of 9408.
2048=2×2×2×2×2×2×2×2×2×2×2
Prime factors of 2048 are 2,2,2,2,2,2,2,2,2,2,2.
Out of the prime factors of 2048, only one 2 is without a pair.
So, 2 is the number by which 2048 must be divided to make the quotient a perfect square.
⇒20482=1024
√1024=32
Hence, the smallest number is 2, which when divides 2048, the quotient is 1024 which is a perfect square.
Hence, the correct answer is 2.