Lamarck proposed two ideas to explain a. how organisms change through time. b. the principles of geology. c. the age of the earth. d. the slow movement of the earth's tectonic plates.

The appropriate response is A. Lamarck is best known for his Theory of Inheritance of Acquired Characteristics, first exhibited in 1801. In the event that a life form changes amid life with a specific end goal to adjust to its condition, those progressions are passed on to its posterity.

Lamarck proposed the theory of acquired inheritance i.e., acquired characteristics. According to this theory, the characteristics which a person acquires, or develops during his/her lifetime, are passed onto the offsprings.Ths, the correct answer is A.

The answer would be sand and gravel