Which of the Following Statements Is True

question 18

Multiple Choice

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.

---

Definitions:

Choroid

A vascular layer of the eye between the retina and the sclera, providing oxygen and nourishment to the outer layers of the retina.

Lens

A transparent structure in the eye that focuses light onto the retina to produce clear images.

Vitreous Humor

A transparent, gel-like substance filling the space between the lens and the retina of the eye, helping it maintain shape and optical properties.

Cornea

The clear, dome-shaped surface that covers the front of the eye and contributes to the eye's focusing power.