Switch to absolute superlatives form :
(a) miguel y maru están muy cansados.
(b) felipe es muy joven.
(c) jimena es muy inteligente.
(d) la madre de marissa está muy contenta.
(e) estoy muy aburrido.

The right answers are:

A. Cansadísimos.

B. Jovencísimo.

C. Inteligentísima.

D. Contentísima.

E. Aburridísimo.    

Explanation: Just to elaborate a little on the answer, it can be added that in order to switch to the superlative forms of these specific adjectives—which can be translated as tired, young, intelligent, happy, and bored—as well as of other adjectives and various adverbs (cerca and lejos, near and far, for example), it is necessary to add the suffix -ísimo, ma, which comes from the Latin -issĭmus, which is also used in that language to form the superlative form.