Question

please i need help with these two questions 1. which of the following causes a precipitate to form?
a. volcanoes erupting and magma cooling
b. lava crystallizing
c. minerals undergoing changes in pressure
d. atoms combining in a solution to form a solid
2. which of the following is true of minerals?
a. grown by farmers when needed
b. cannot be used to generate electricity
c. used in industries to build products
d. always found in groups
any help would greatly be appreciated thanks

Answer 1

so i think 1, - b
2. - c

- but not is sure