I would say para. Because para means "to" and the sentence is saying "my brother bought a bike to ride in the mountains"
1. A
2. B
3. B
4. C
5. C
6. A
7. C
8. B
Yo necesito verte manana.
B) esta. esta typically refers to describing something like location whereas es describes the person's attributes. (ie, esta would be used with "she is in the store" and es would be used with "she is cute"