Hi!
Your answer is B.
It is <u><em>not</em></u> A because this doesn't really make sense. It's not the best answer.
It <u><em>is</em></u> B because, in sentences, the words around it will likely give the information you need to infer what the word means.
(For example, if I were to say "<em>She was </em><u><em>continuously</em></u><em> singing, for yesterday she sang for 4 straight hours, and it was extremely annoying</em>", pretend you do not know what "continuously" means. By using the words around it, such as "4 straight hours" you can predict that it means "never stopping".)
It is <u><em>not</em></u> C because not every single sentence contains a synonym or antonym.
(See the sentence above. The antonym of "continuously" would be 'never' or 'sometimes' or possibly 'discontinous'. There isn't always an antonym or synonym there, is there?)
It is <u><em>not</em></u> D because not every single word is defined in a passage.
(When you open an average book, is there just an entire page(s) dedicated to every single definition of a word? Most often, no, there is not.)
The modern evolutionary synthesis leaves unresolved some of the most fundamental, long-standing questions in evolutionary biology: What is the role of sex in evolution? How does complex adaptation evolve? How can selection operate effectively on genetic interactions? More recently, the molecular biology and genomics revolutions have raised a host of critical new questions, through empirical findings that the modern synthesis fails to explain: for example, the discovery of de novo<span> genes; the immense constructive role of transposable elements in evolution; genetic variance and biochemical activity that go far beyond what traditional natural selection can maintain; perplexing cases of molecular parallelism; and more.</span>
