Answer:
Option B. 
Step-by-step explanation:
we know that
The frequency is equal to the number of cycles divided by the time
Remember that
1 cycle = 1 full wave to repeat itself
In this problem
From o to 12 seconds ------> there are 2 cycles
therefore
The frequency is equal to

Depending on the player, a spectator can figure out the chance of the player making the basket :D
Answer
h = 8.12 cm
Explanation
Area of a parallelogram = b • h
We know the area is 20.3 cm^2 and that the base is 2.5cm.
Therefore 20.3 cm^2 = 2.5h
20.3/2.5 = 8.12 cm
h = 8.12 cm