Rene owns four small businesses. Rene spends the following number of hours this year working in those businesses which is more than any other employee of the businesses: Business A, 105 hours; Business B, 130 hours; Business C, 120 hours; Business D, 99 hours. Which of the following statements is correct?

a. Businesses A, B, and C are material participation activities.

b. Businesses A, B, C, and D are all significant participation activities.

c. Businesses A, B, and C are significant participation activities.

d. Both a. and c. are correct.