Which of the following BEST describes the best Exponential function below.

Answer:
[tex]y=4\cdot0.5^x[/tex]Step-by-step explanation:
An exponential decay describes the process of reducing an amount by a consistent percentage rate over a period of time. It can be represented by the equation:
[tex]\begin{gathered} y=ab^x \\ \text{where,} \\ \text{ y= final amount} \\ \text{ a= original amount} \\ \text{ b= decay factor b<1} \end{gathered}[/tex]Therefore, the function that best describes the function above would be:
[tex]\begin{gathered} \text{ Decay: } \\ y=4\cdot0.5^x \end{gathered}[/tex]