Which of the following illustrates 2 resistors in a series circuit

Option B is the correct.

Explanation:

In a series circuit, components are connected end-to-end in a line to form a single path through which current can flow.

In the diagram, option B and D, both are series circuits but circuit B has two resistors while circuit D has only one.

Circuit A and C are parallel circuits because their components are connected across each other's leads. They have many paths for current flow with one voltage across all components.

So, circuits A, C, and D are incorrect.

explanation:

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation: