Question

what does mud mean to a geologist? in other words, which categories are lumped together and called mud?
silt and clay
sand and silt
sand, silt and clay

Explanation:

In geology, mud is defined as a mixture of fine - grained particles. Silt and clay are both fine - grained sedimentary particles. Sand is a coarser - grained particle and is not part of the definition of mud. So the categories lumped together as mud are silt and clay.

Answer:

A. silt and clay