Which of the following is NOT a way to transmit STIs?

a. through pregnancy

b. indirectly touching sex organs

c. sharing a dinner utensil

d. exposure to an open sore

Indirectly touching sex organs is not a way to transmit STIs. The correct option among all the options that are given in the question is the second option or option "b". STIs are spread mainly through direct sexual intercourse. It can also spread through contacts with open wounds of a person having STI.