A) According to the Social Security Administration – You can replace your Social Security card for free if it is lost or stolen. However, you may not need to get a replacement card. Knowing your Social Security number is what is important.
You need a Social Security number to get a job, collect Social Security benefits and receive some government services but you do not often need to show your Social Security card.
More information here http://www.socialsecurity.gov/ssnumber/ss5.htm