it is often hard to practice self-control when eating in the company of others because people are greatly influenced by which of the following

a peers
b environment
c appearance of food
d hunger

All of the above.

a peers: People may be influenced by what others around them are eating or how much they are eating, leading to a lack of self-control.
b environment: The environment in which people are eating can also influence their self-control. For example, if they are in a social setting where indulging in unhealthy foods is the norm, they may find it difficult to resist.
c appearance of food: The way food is presented can also impact self-control. If the food looks appetizing or visually appealing, people may have a harder time controlling their impulses and portion sizes.
d hunger: If people are extremely hungry, they may struggle to practice self-control and end up eating more than they intended to, regardless of the other factors mentioned above. Overall, self-control can be difficult to maintain when eating in the company of others due to the influence of peers, environment, appearance of food, and hunger.