The graph shows the forecast wind speed (in $\mathrm{km} / \mathrm{h}$ ) during a 7 -day period. Jack can sail alone only when the forecast wind speed is less than $20 \mathrm{~km} / \mathrm{h}$. During this 7-day period, on how many days will Jack be able to sail alone?
(A) 4
(B) 6
(C) 1
(D) 2
(E) 5

![](https://cdn.mathpix.com/cropped/2024_04_20_6027bc27089ed4fc493cg-002.jpg?height=323&width=458&top_left_y=603&top_left_x=1278)
Reading from the graph, the forecast wind speed is less than $20 \mathrm{~km} / \mathrm{h}$ on Monday, Tuesday, Wednesday, and Sunday.

Thus, Jack will be able to sail alone on 4 days during this 7 -day period.

ANSWER: (A)