Use the Multiplication Principle to Solve the Problem $1,000,000$ B) $10,000,000$ C) $9,000,000$

Multiple Choice

Use the multiplication principle to solve the problem.
-How many different 7 -digit phone numbers are possible if the first digit cannot be a 0 ?

A) $1,000,000$
B) $10,000,000$
C) $9,000,000$
D) 900,000