Question

the names of geological eras uniformly describe phases in earths evolutionary history (e.g., phanerozoic means \abundant life\). names given to geological periods, —— are of diverse origins. the permian period is named after the historical region of perm in russia, for example, while the silurian period takes its name from the celtic tribe the silures. which choice completes the text with the most logical transition? a therefore, b in turn, c on the other hand, d furthermore,

Explanation:

"in turn" is used to show a sequence or a reciprocal relationship. Here, it is used to continue the description of how geological - period names are derived in a logical flow. "therefore" implies a cause - and - effect relationship which is not applicable here. "on the other hand" is used for presenting an alternative or contrasting view. "furthermore" is for adding additional information. The context requires a word to show a sequential and logical continuation, and "in turn" fits best.

Answer:

B. in turn