Suppose That the Current One-Year Rate (One-Year Spot Rate) and Expected

Suppose that the current one-year rate (one-year spot rate) and expected one-year T-bill rates over the following three years (i.e., years 2, 3, and 4, respectively) are as follows: $${ } _ { 1 } R _ { 1 } = 5 \% , \quad E \left( { } _ { 2 } r _ { 1 } \right) = 5.5 \% , \quad E \left( { } _ { 3 } r _ { 1 } \right) = 6.5 \% \quad E \left( { } _ { 4 } r _ { 1 } \right) = 7.0 \%$$ Using the unbiased expectations theory, what is the current (long-term) rate for four-year-maturity Treasury securities?

A) 6.00 percent
B) 6.33 percent
C) 6.75 percent
D) 7.00 percent