Which of these is essential to netiquette?
set all your social media accounts to private.
do not give your contact details to strangers.
do not use offensive language.
visit only trusted websites.

C  Do not use offensive language

Explanation:

For plato users

these are common warning signs of overtraining syndrome:

washed-out feeling, tired, drained, lack of energy

mild leg soreness, general aches, and pains

pain in muscles and joints

sudden drop in performance

insomnia

headaches

decreased immunity (increased number of colds, and sore throats)

decrease in training capacity/intensity

moodiness and irritability

depression

loss of enthusiasm for the sport

decreased appetite

increased incidence of injuries.

a compulsive need to exercise

the trait of personality falls in the middle of the diagram because personality is a mixture of ones nature and environment.