The following results were gathered from a survey where three toothpaste brands were tested by three groups.

The following results were gathered from a survey where three toothpaste brands were tested by three groups. (For example, when 50 people tried Brand A toothpaste for a year, they got zero to one new cavities.)

Determine if there is a significant difference in the effectiveness of these toothpastes in preventing cavities.

Select the appropriate conclusion.

Select one:

a. At an alpha of 0.05 there is a significant difference in the effectiveness of these 3 brands of toothpastes. Brand and cavities are not independent.

b. At an alpha of 0.25 there is NOT a significant difference in the effectiveness of these 3 brands of toothpastes. Brand and cavities are independent.

c. At an alpha of 0.5 there is NOT a significant difference in the effectiveness of these 3 brands of toothpastes. Brand and cavities are independent.

d. At an alpha of 0.2 there is a significant difference in the effectiveness of these 3 brands of toothpastes. Brand and cavities are not independent.

I got D and would to verify.