Estábamos sirviendo would be the answer for the nosotros form in the imperfect progressive. For future reference, you should check out the Spanish Dict online, it has all of the verbs in every form and tense :)
The correct answer is b, hope that helps
A: nosotros hemos resuelto comer menos.
Good evening, comrades, Yours sincerely, would be so ambles to help with the Spanish, which is the following
