Step 1: Current allocation.
Bihar sends 40 members to the Lok Sabha. The overall house strength is 543 elected members.
Step 2: Note on delimitation/federal changes.
Post creation of Jharkhand (2000) and subsequent delimitation exercises, Bihar’s current allocation stands at 40.
Step 3: Conclude.
\[
\boxed{\text{40 seats (Option A).}}
\]