Which of the Following Statements Is True

Which of the following statements is true?

A) A truncated regression is a special case of a random sample selection.
B) Nonrandom sample selection can arise in cases of cross-sectional and time series data, but not in the case of panel data.
C) The Tobit regression model is based on endogenous sample selection.
D) The censored regression model is based on nonrandom sample selection.