Which pronoun correctly completes the sentence?

congratulate finished the challenging obstacle course.

a.
whoever

b.
whomever

the difference between an explicit and implicit meaning is that the explicit meaning of a poem is that the detail is exactly defined. nothing is left to interpretation. an implicit meaning is an implied meaning. kabir's poetry is both explicit and implicit in that it can be interpreted on different levels. the explicit meaning leaves nothing to interpretation while the implicit meaning leaves lots open to interpretation. an example of this is found in the poem "rumi and the spiritual lover". 

hey kid learn to actually put time and effort into your school work and maybe you would get higher grades and not have to come on this website and beg for answer's