Respuesta :
The answer is C. "The rings of Saturn contain mostly ice and rock."
For A, notice that "astronauts" is plural, but "has" is singular.
For B, notice that "Saturn" is singular, and Jupiter and Uranus are not part of the subject, and "have" is plural.
For C, notice that "rings" is plural, and "contain" is plural.
For D, notice that "purpose" is singular, but "missions" is plural.
For A, notice that "astronauts" is plural, but "has" is singular.
For B, notice that "Saturn" is singular, and Jupiter and Uranus are not part of the subject, and "have" is plural.
For C, notice that "rings" is plural, and "contain" is plural.
For D, notice that "purpose" is singular, but "missions" is plural.