a) No. The stats from the Red States with their fondness for abstinence-based non-sex-ed and skyrocketing teen pregnancy rates provide an easy counter to that argument.
b) Listen, if there was an STD that caused spontaneous human combustion, we'd still be out there having unprotected sex. No one thinks bad things are going to happen to them - and teenagers more so than the rest of us.
c) Again, see Red States for what happens when socially conservative agendas are followed. Parents who want to shelter their children from reality are fighting a losing battle, especially once their precious little snowflakes hit college.