Context: The passage below describes an experiment. Read the passage and think about the variables that are described.

Lamar liked to hike, but he was often bothered by mosquito bites. He read that rubbing lavender flowers on your skin can repel mosquitoes. Lamar wanted to find out if lavender flowers work better as a mosquito repellent than store-bought bug spray. So, he sprayed bug spray on one of his arms and rubbed lavender flowers on his other arm. Then, he went for a hike.
When he got home, he counted the number of new mosquito bites on each arm. Lamar repeated this test each afternoon for one week.
Hint: An independent variable is a variable whose effect you are investigating. A dependent variable is a variable that you measure.
Figure: a mosquito biting a human.
Which of the following was an independent variable in this experiment?
A. the number of mosquito bites
B. the type of mosquito repellent used
Determine the correct option from the provided choices and reply with its corresponding letter.

B