I need explanation step by step

A couple invests $3500 to build a rose garden. On the average, it costs them $0.35 to grow each rose and each rose can be sold for $1.75. Use this information to answer questions 6 and 7. 6. Create a formula for a cost function and a revenue function, both in dollars. Let x be the number of roses sold. (A) C(x) =1.75x and R(x) = 0.35x (B) C(x) =1.75x+3500 and R(x) =0.35x (C) C(x) =0.35x+3500 and R(x) =1.75x (D) C(x) =0.35x and R(x) = 1.75x (E) C(x) =3500 and R(x) = 1.40x 7. How many roses must the couple sell to break even? (A) 2,000 (B) 2,500 (C) 10,000 (D) 8,250 (E) None of these