Write a formula for the general or $n^{\th}$ term of the geometric sequence where $a_7=1458$ and $r=-3$.

• A. $a_{n}=1\cdot\left(-3\right)^{n-1}$
• B. $a_{n}=2\cdot\left(-3\right)^{n-1}$
• C. $a_{n}=-\frac23\cdot\left(-3\right)^{n-1}$
• D. $a_{n}=\frac23\cdot\left(-3\right)^{n-1}$