Answer :

As given by the question

There are given that the sequence:

[tex]64.5,\text{ 65, 65.5, 66, 66.5,}\ldots[/tex]

Now,

From the formula of the nth term of the arithmetic sequence:

[tex]a_n=a_1+(n-1)d[/tex]

Where,

[tex]\begin{gathered} a_1=65, \\ d=a_2-a_1 \\ d=65.5_{}-65 \\ d=0.5 \end{gathered}[/tex]

Then,

Put all the terms into the above formula:

So,

[tex]A=0.5n\ldots\text{.}(1)[/tex]

Now,

If the first term is 65

Then,

[tex]65-0.5=64.5[/tex]

Then,

Add the above value into equation (1)

So,

[tex]A=0.5n+64.5[/tex]

Hence, the correct option is C.