Let $T$ be an linear transformation from ${\mathbb R}^r$ to ${\mathbb R}^s$. Let $A$ be the matrix associated to $T$.

Fill in the correct answer for each of the following situations.

 1. Every row in the row-echelon form of $A$ has a pivot.
 2. Two rows in the row-echelon form of $A$ do not have pivots.
 3. The row-echelon form of $A$ has a row of zeros.
 4. The row-echelon form of $A$ has a pivot in every column.

A. T is onto
B. T is not onto
C. There is not enough information to tell.