The answer is D. un.
Làpiz is a masuline word in Spanish, so "la" and "una" cannot be used since those are feminine. "Los" is also incorrect since that is the plural form, which is not being used in the sentence. Therefore, un is the correct choice.
Mexico almost all the Mexicans want to go to miami
Well, there are 3 types of verbs - those ending in ar, er, and ir
For the present tense, they are conjugated like this
An ar verb - bailar (to dance)
Remove the -ar- and add the ending
the conjugations will be
I - bailo
You- bailas
He/she- baila
We- bailamos
you pl- bailáis
they- bailan
Then an -er verb - comer (to eat)
Again, remove the er and add ending
I- como
You- comes
he/she- come
we- comemos
you pl - coméis
they - comen
Ir verbs - vivir (to live)
Remove -ir and add ending
I- vivo
you -vives
he/she - vive
we- vivimos
you pl. -vivís
they- viven
These are for the present tense only, hope this helps!