A matrix A=(210021002)A = \begin{pmatrix} 2 & 1 & 0 \\ 0 & 2 & 1 \\ 0 & 0 & 2 \end{pmatrix}A=200120012 is upper triangular. What can we conclude about its rank?
rank(A)=1\text{rank}(A) = 1rank(A)=1 (at most one linearly independent row)
rank(A)=2\text{rank}(A) = 2rank(A)=2 (exactly two linearly independent rows)
rank(A)=3\text{rank}(A) = 3rank(A)=3 (all three rows are linearly independent)
Rank cannot be determined from this information alone