For this case we can translate the sentence given as:
They (have) many problems last year.
If we conjugate the verb "tener" in imperative mode in simple preterite (Verb tense that expresses an action finished in the past) we have:
yo tuve
tú tuviste
él/ella/Ud. tuvo
nosotros tuvimos
vosotros tuvisteis
ellos/ellas/Uds. tuvieron
Then, it is observed that the correct option is A. "Ellos tuvieron muchos problemas el año pasado"
ANswer:
Option A