Supplementary angles are two angles that add up to 180 degrees. If \( m∠b = 98° \), then to find \( m∠a \), you can use the following equation:
\[ m∠a + m∠b = 180° \]
Substituting the given value:
\[ m∠a + 98° = 180° \]
Now, subtract 98° from both sides:
\[ m∠a = 180° - 98° = 82° \]
So, \( m∠a = 82° \).
The correct response is 82°.