When driving in very thick fog, are we obliged to have the front fog lights switched on?

When driving in very thick fog, are we obliged to have the front fog lights switched on?
A)No.Correct
B)Yes.
The installation of front fog lights is optional on vehicles, so their use is also optional.
FRONT FOG LIGHT:
- Its installation and use is NOT mandatory.
- It will be white or selective yellow.
- It will be used, voluntarily, in case of fog, heavy rain, snowfall, smoke or dust clouds, or in similar circumstances.
- It can also be used on narrow roads with many curves, that is, those with a roadway 6.5 m wide or less, signposted with «dangerous curves» signs.
REAR FOG LIGHT:
- Its installation and use is mandatory.
- It will be red.
- It will be used, mandatorily, in case of THICK fog, VERY heavy rain, HEAVY snowfall, or DENSE clouds of smoke or dust.
In the case of the question, where the fog is very thick, we must drive with position lights together with low-beam headlights, front fog lights optionally if we have them, and the rear fog light mandatorily.