Sam multiplies a number, n, by a two-digit number. Which statement is true
a. When n is a four-digit number, the product will have five or six digits.
b. When n is a one-digit number, the product will always have three digits.
c. When n is a three-digit number, the product will always have four digits.
d. When n is a two-digit number, the product will have four or five digits.