HELP ASAP PLZZZ please keep it in simple words I am foundation paper

This question is about substances with covalent bonding. Suggest one limitation of using a ball and stick model for a water molecule.

What rule is used to determine how many covalent bonds an element can form? a. the number of covalent bonds is equal to six c the number of covalent bonds is equal to five minus the group number plus the group number b. the number of covalent bonds is equal to eight d. none of the above minus the group number select the best answer from the choices provided