At what age must a person be to be guilty of knowingly engaging in sexual contact with another person if the other person is underage?

The correct answer is 16 because South Dakota law establishes the age of consent as 16 years old. This means that individuals who are 16 years old or older can legally consent to sexual activity. If someone engages in sexual contact with another person who is under the age of 16, they can be found guilty of a crime under the state's laws, as the younger individual is not legally recognized as able to give consent. Therefore, it is crucial to understand that the legal implications of sexual contact hinge on the ages of those involved, particularly focusing on the protection of minors who are not yet at the legal age of consent.