John and Susan Smith are in their mid 30s and have two children, a 4-year-old and a 2-year-old. Both John and Susan work and do not currently need additional income. They have determined they want to conservatively invest so that they will have funds for their childrens' college in about 12-15 years. Which of the following investments would best meet their goal? A) Common Stocks.B) Laddered Treasury Notes.C) Laddered Zero-Coupon Bonds.D) Preferred Stocks.