The degree of static indeterminacy (DSI) is calculated by the formula:
\[
DSI = m + r - 2j
\]
Where:
- \( m \) is the number of members,
- \( r \) is the number of reactions,
- \( j \) is the number of joints.
For this truss, the DSI is 0, meaning the truss is statically determinate. Hence, the correct answer is 0.