What part of the brain is responsible for thought, reasoning, memory, judgment, speech, and voluntary movement?

The answer is "cerebrum".

The cerebrum refers to the most superior and front of the mind's significant areas. It is the seat of reason, arranging, memory, and tangible coordination. All cognizant idea starts in the cerebrum and can impact the intuitive elements of the lower areas of the brain. Cerebrum, the biggest part of the mind.