Choice B is correct. It’s given that in a group, $40 percent sign$ of the items are red. It follows that the number of red items in the group can be represented by $0 period 4 x$ , where $x$ represents the total number of items in the group. It’s also given that of all the red items in the group, $30 percent sign$ also have stripes. It follows that the number of items in the group that are red and have stripes can be represented by $0 period 3 left parenthesis 0 period 4 x right parenthesis$ , or $0 period 12 x$ . The expression $0 period 12 x$ represents $12 percent sign$ of $x$ . Since $x$ represents the total number of items in the group, it follows that $12 percent sign$ of the items in the group are red and have stripes.

Choice A is incorrect and may result from subtracting $30 percent sign$ from $40 percent sign$ rather than calculating $30 percent sign$ of $40 percent sign$ .

Choice C is incorrect and may result from adding $30 percent sign$ and $40 percent sign$ rather than calculating $30 percent sign$ of $40 percent sign$ .

Choice D is incorrect and may result from calculating the percentage that $30 percent sign$ is of $40 percent sign$ rather than calculating $30 percent sign$ of $40 percent sign$ .