I would say D because it involves more selection but if that one is wrong it is most likely B. But I would go with D
Explanation: If the rate of photosynthesis increases, then the number of bubbles will increase.
Starch blocker help prevent the body from absorbing starches so you don't absorb calories, and fat blockers are kind of the same thing, they don't let your body absorb fat, instead it excretes it as waste.
Before higher education, American students attend elementary and high school for a combined total of 12 years. These years are known as the period from first grade to twelfth grade.
At the approximate age of six, American children begin elementary school, which is exclusively called “elementary school” (elementary school). They attend this school for five or six years and then go on to high school.
High schools are made up of two programs: the first is called "middle school" or "high school" (middle school) and the second is called "high school" (high school). A diploma or certificate is awarded upon graduation from high school. Upon graduation from high school (twelfth grade), American students can go on to college or university. Studies at a college or university are known as "higher education."