All the options are conjugations of the verb hacer in the imperfect tense. This tense is used to talk about past actions, conditions, or events that occurred regularly or frequently or that were in progress in a moment in the past. Since <em>mis hermanos </em>can be replaced by <em>ellos</em>, which is the subject pronoun that matches the third person plural, we need to choose the conjugation of the verb hacer that also matches this person, which is hacían. Finally:
<em>Mis hermanos </em><em>hacían</em><em> la cena en la cocina</em>
It's Fuerte for man and woman same as one person or other but if you have multiple-choice and is not in there then it has to be Fuertoso singular and for plural fuertes or fuertosos. they are less common do. Hope I had helped.