Linear functions never have maxima and minima, so a) is discarded.
In the options there are quadratic functions, they can present either a maximum or a minimum.
You can know instantly by seeing the sign of the variable
, <em>if positive the parabola opens up</em>, <u>then it will have a minimum</u>, <em>if negative the parabola opens down</em>, <u>having a maximum.</u>
