Please help. You have to write a paragraph! I will delete if you don’t! I will also mark brainliest!

Fill the blank with a la, a las, a los, or al. mi padre .

Okay so i'm taking an online spanish course (penn foster), and in the study guide, you have to create a bunch of sentences with words you've learned so far. translating, reading, and those kinds of things are fairly easy, but when it comes to making my own sentences, my brain just kinda waltz's away. anyone got any tips?

No debemos el medio ambiente. a. contaminar b. preservar c. desechar d. cumplir