Answer: B. taking the first complete cores of deep-sea sediments.
Step-by-step explanation:
The Glomar Challenger was regarded as the first research vessel that was designed for drilling into the ocean and then take core samples from it.
Therefore, based on the options given, the Glomar Challenger (Joides Resolution) is known mainly for taking the first complete cores of deep-sea sediments.
Therefore, the correct option is B.