The magnification of a plane mirror is +1. What does this signify?

Question

$\begin{array}{1 1} (a)\; \text{It signifies that the image formed is real, inverted and same size as that of the object} \\ (b)\; \text{It signifies that the image formed is virtual, erect and same size as that of the object} \\ (c)\; \text{It signifies that the image formed is real, erect and same size as that of the object} \\ (d)\; \text{It signifies that the image formed is virtual and inverted and same size as that of the object} \end{array}$