An Equation in the Simultaneous Equations Model Satisfies the Order

An equation in the simultaneous equations model satisfies the order condition for identification if:

A) the number of excluded endogenous variables from the equation is at most as large as the number of right-hand side exogenous variables.
B) the number of excluded endogenous variables from the equation is at least as large as the number of right-hand side exogenous variables.
C) the number of excluded exogenous variables from the equation is at most as large as the number of right-hand side endogenous variables.
D) the number of excluded exogenous variables from the equation is at least as large as the number of right-hand side endogenous variables.