Worst thing in online chess

So tell which one when you have only 10sec left and no increment:
a) Mouse slip and you blundered
b) Internet connection lost
c) Mouse stopped working
d) device got hanged
Which one is the worst for you

a! I sometimes do mouseslip on casual and can't ask for takeback because they wont reply in time and i will beserk

B) internet connection lost

all of them

Option B

i feel a] and b] are most common but d] is the worst when it happens[rarely]

d) device got hanged

Option A for me.
Once in an online tournament I mouse slipped 4 times

a lol