True about nerve injuries among following are:

Froment sign (Fig a-normal, b- positive) Seen in ulnar nerve palsy due to action of FPL which is supplied by median nerve. Waenberg sign (c- normal, d- positive) Seen in ulnar nerve palsy and not median nerve palsy so this option is wrong. It is caused by an unopposed action of the ulnar inseion of the extensor digiti minimi(radial nerve innervation). It occurs due to paralysis of the palmar interosseous muscle that abducts the little finger. Only lateral two lumbricals are supplied by median nerve medial two lumbricals are supplied by ulnar nerve.