Your formal singular in Spanish is -tu singular formal-
ser- to be
1. Los perros son mascotas
the dogs are pets
2.
3. Mis padres son muy guapos
my parents are very pretty
For your information, conjugation means the adaptation of ir/er verbs in Spanish to suit who is performing it. (to --- verbs)
eg.
comer- to eat
como- i eat
comes- you eat
come- he or she eats
.
.
.
these can be followed on by yo,tu,ella/el though is not necesary
1. C
2. A
3. C
4. (I can’t see the last two options, but the answer is “agencia de viajes”)