What Was the Basis of President James Polk's Concerns About

What was the basis of President James Polk's concerns about General Zachary Taylor?

A) Polk knew Taylor had a poor grasp of military tactics.
B) Polk believed Taylor was sympathetic to the enemy.
C) Polk worried that Taylor harbored political aspirations.
D) Polk believed Taylor lacked control over his undisciplined soldiers.
E) Polk was disgusted by Taylor's habit of wearing an old and dirty uniform.