The Summer Olympics are held once every 4 years. During an 18 year period, what is the largest number of Summer Olympics that could be held?
(A) 3
(B) 4
(C) 5
(D) 6
(E) 7
Two consecutive Summer Olympics are held 4 years apart.

Each successive Summer Olympics requires an additional 4 years before it is held.

We use this to summarize the minimum time required for the largest number of Summer Olympics to be held, as shown.

| Number of Summer Olympics | Minimum Number of Years Apart |
| :---: | :---: |
| 2 | 4 |
| 3 | 8 |
| 4 | 12 |
| 5 | 16 |
| 6 | 20 |

From the table above, we see that at least 20 years are required to host 6 Summer Olympics, while only 16 years are required to host 5 .

(For example, the 5 olympics could be held in years $1,5,9,13$, and 17.)

Therefore, the maximum number of Summer Olympics that can be held during an 18 year period is 5 .

ANswer: (C)