A recipe for salad dressing uses 5 ounces of oil for every 2 ounces of vinegar. If a restaurant needs to make exactly 35 ounces of salad dressing, how many ounces of oil will it need?
A. 10
B. 14
C. 15
D. 25

Step 1 ：The problem is asking for the amount of oil needed to make 35 ounces of salad dressing. The ratio of oil to vinegar is 5:2. This means that for every 7 ounces of salad dressing (5 ounces of oil + 2 ounces of vinegar), 5 ounces of oil are used.

Step 2 ：To find out how much oil is needed for 35 ounces of salad dressing, we need to set up a proportion and solve for the unknown.

Step 3 ：First, we calculate the ratio of oil in the total dressing, which is \(\frac{5}{5+2} = 0.7142857142857143\).

Step 4 ：Then, we multiply this ratio by the total amount of dressing needed, which is \(0.7142857142857143 \times 35 = 25.0\).

Step 5 ：So, the restaurant will need 25 ounces of oil to make 35 ounces of salad dressing.

Step 6 ：Final Answer: \(\boxed{25}\)