A particle is pushed by forces `2hati + 3hatj -2 hatk and 5hati -hatj - 3hatk` simultaneously and it is displaced from point `hati + hatj + hatk` to point `2hati - hatj + 3hatk`. The work done is
Options:
(a) 7 units
(b) —7 units
(c) 10 units
(d) -10 units