D. Much too cool/cold and not that good precipitation either.
The upgrade from subarctic to warm summer humid continental does increase its grade a bit: indeed, the summer months need the least temperature increase of all the months to get an A from me.
Here's how I would change it to get an A climate. My A climate is quintessential 4 season Dfa/Dfb Oshawa.
https://en.wikipedia.org/wiki/Oshawa#Climate
In a nutshell, warmer in all seasons to be comparable to Oshawa, reduce the amount and number of months with snow, and make the precipitation more even (the amount falls into my preferred range, but I like the distribution even like Oshawa, not warm season heavy like Pickle Lake).