A most common cause of tarsal tunnel syndrome -
Amongst the given options, RA is the most common cause of tarsal tunnel syndrome.

Facts about etiology of tarsal tunnel syndrome

Most common origin of tarsal tunnel syndrome is idiopathic (21-36%).
When the cause is known, trauma is the most common cause.
Two most common systemic causes of tarsal tunnel syndrome are diabetes (m.c.) and RA (2nd m.c.)
Osteoarthritis
Ankylosing spondylitis
Psoriatic arthritis
Rheumatoid arthritis