Option A. = 9
Step-by-step explanation:
Factors of a number are numbers you Multiply to get another number.
For example:
The factors of 6 are 2 * 3
The factors of 18 are 1*18, 2*9, 3*6,
Also,
The factors of a number, are numbers that can divide through another number perfectly without a remainder
With that knowledge:
The factors of 162 are:
1*162, 2*81, 3*54, 9*18 etc
If you observe well, of all the options, only 9 appears.
Hence 9 is the correct answer.
Option A