Exactly A & C. And for that price, it's probably only 70 dollars more expensive to obtain than an 'egg timer' from Sporty's etc. After all, most PPL's I know think nothing of splashing out thousands on a Breitling ELT timepiece or the like...
As they say, mark 1 eyeballs and a clock. There's no substitute!
https://www.sportys.com/PilotShop/product/9226 Expensive and not as good as a basic installed clock. I've known these to go missing from rental aircraft.
Edit:
Or there is this one.
MITCHELL LIGHTED QUARTZ ELECTRIC CLOCK from Aircraft Spruce