The degree of the polynomial ma²b³ + 6ab² - m is

1. 6
2. 5
3. 3
4. 2

The degree of a term is the sum of the powers of its variables. The degree of the polynomial is the highest degree among its terms.

Term 1 (ma²b³): 1 + 2 + 3 = 6

Term 2 (6ab²): 1 + 2 = 3

Term 3 (m): 1

Here, term 1 has the highest degree i.e., 6

Hence, option 1 is the correct option.