Hello There! ^_^
Your question: Which one of the following times would be the longest..?
You answer: The Paleozoic Era would be the longest time span.
the answer is option B.
Hope this helps!
<span>If you see a very tall, rock feature that looks like a jagged, rectangular block sticking out of the ground, you're probably observing a volcanic neck. Also known as a lava neck or volcanic plug, a volcanic neck is formed when magma solidifies within a vent of an active volcano. This can harness great amounts of pressures which could lead to an explosive eruption.</span>