Answer:
see below
Explanation:
The coefficients are 19Cr for r from 0 to 19, as shown in the first and last choices. The sum of the powers of the factors is 19, as shown in the first and last choices. The only difference between the first and last choices is the order of terms in the sum. Both have the same total, and both are equivalent expansions of the given expression.
If you prefer the higher powers of m to appear first, then the last choice is appropriate.