La tienda would be the correct answer.
You're correct, the answer is D. tomo.
How I remember it is this, in Spanish, "yo" means "I", "yo" has an "o" at the end of it and nearly all conjugations that need to be conjugated to "I ____." will have an "o" at the end!
El microbús y bicicletas son medios de transportes.
The answer is “sobre” :) hope that helps