Since ray AC bisects angle A, it means that angle BAC and angle DAC are equal. Given that \( m\angle BAD = 46^\circ \), we can express \( m\angle A \) as follows:
\[ m\angle A = m\angle BAC + m\angle DAC \]
Since \( m\angle BAC = m\angle DAC \), let \( m\angle BAC = x \). Thus, we have:
\[ m\angle BAD + m\angle DAC = m\angle A \]
Substituting these values gives us:
\[ 46^\circ + x = 2x \]
Solving for \( x \) gives:
\[ 46^\circ = 2x - x \] \[ 46^\circ = x \]
Thus, the measure of angle BAC is:
\[ m\angle BAC = 46^\circ \]
Therefore, the correct response is:
The \( m\angle BAC \) is 46 degrees.