Which of the following most correctly identifies the roles of vascular tissues? and why?

a. Xylem conducts H2O and dissolved minerals up to the leaves, where phloem transports the products of photosynthesis down a stem.
b. Phloem conducts H2O and dissolved minerals up to the leaves, where xylem transports the products of photosynthesis down a stem.
c. Xylem conducts H2O and dissolved minerals up to the leaves, where phloem transports the products of photosynthesis away from the leaves.
d. Phloem conducts H2O and dissolved minerals up to the leaves, where xylem transports the products of photosynthesis away from the leaves.