Answer: signal phrases should provide just enough information to show the reader that this source is a valid one and that can be trusted.
Step-by-step explanation:
Signal phrases are simply used to show that a quote will soon be introduced. Signal phrases helps in the introduction of information which are gotten from outside source.
Among the options given, the correct answer is that "signal phrases should provide just enough information to show the reader that this source is a valid one and that can be trusted".