C. since sexual reproduction takes a lot longer and it involves 2 offsprings. it requires more energy
Answer A seems like the best choice for this question. Just think about some of the synonyms for therefore—”hence,” “consequently,” and “thus.” Because the adverb therefore often plays the role of a conjunction, it's sometimes called a conjunctive adverb.
B isn’t the correct answer to this question because you use “On the other hand” to introduce two contrasting points, facts, or ways of looking at something.
C isn’t the correct answer because we are not comparing or contrasting anything in this sentence.
D isn’t the correct answer because “Especially” is used in a formal sentence example: She can't be sure she will win, especially at this early stage of the campaign.
Computer Science is the correct answer. Computers were relatively new in the early 1950s. As the field of computer science advanced, they learned how computers send, receive, process, store, and retrieve information. The founder of Cognitive Psychology was able to see that the human mind/brain works in much the same way.