Which of the following is not a vascular plant?
conifer
fern
moss
flowering plant

The answer is moss.

Mosses are nonvascular seedless plants. Nonvascular plants have simple tissues specialized for internal water transport.
On the other side, vascular plants have vascular tissue which consists of xylem and phloem. Xylem transport water and minerals from the root to the upper parts of the plant. Phloem transports food and nutrients from the leaves, where they are produced, to the growing or storage parts of the plants. 

What have scientists learned about plant behavior by studying the dodder plant