Which best explains why blood is considered to be a suspension?
it has nutrients that cannot be dissolved.
it contains particles that can settle out.
it has nutrients that are dissolved in its liquid portion.
it contains particles that mix on a molecular level.

It contains particles that can settle out.

Explanation:

There are following three types of conditions.

a) True solutions: This is homogeneous mixture of two components. Here the size of particle of solute is in between 0.01 -1nm. The components do not separate on standing.

b) Colloids: Heterogeneous mixture. The particle size is 1-1000 nm.The components do not separate on standing.

c) Suspension: Heterogeneous mixture. The particle size is greater than 1000 nm. The components get separated on standing.