What is the largest six-digit number that can be formed with the digits 3, 5, 9, 4, 6, and 2 using each digit only once?

The correct option is B 9,65,432

Arrange the given digits in the decreasing order of their values.
9 > 6 > 5 > 4 > 3 > 2

Place the largest digit at the largest place and arrange the remaining digits in a decreasing order.

Thus, the largest six-digit number that can be formed is 9,65,432.