Which of the following statements is correct?

A Beta coefficient of $2\mathrm{.}0$ means that a stock is twice as risky as the risk$-$free debt security.

A Beta coefficient of $2\mathrm{.}0$ means that a stock is half as risky as the market portfolio.

A Beta coefficient of $1\mathrm{.}0$ means that a stock is as risky as the risk$-$free debt security.

A Beta coefficient of $1\mathrm{.}0$ means that a stock is as risky as the market portfolio.