I need help please. Passage: People's Theater

Which word or phrase fits best at the beginning of the 1st sentence of the 3rd paragraph?

A. In the meantime,
B. Consequently,
C. Moreover,
D. As a matter of fact,

Layer r contains a well-known index fossil that is 100 million years old. based on this information and the principle of superposition, a. layers t and m are older than 100 million years, and layers x and g are younger than 100 million years. b. layers t, m, x, and g are all older than 100 million years. c. layers t and m are younger than 100 million years, and layers x and g are older than 100 million years.