Why not A?

To me, the Meerkat barking while it's running to safety tends to undermine the conclusion that being a sentinel is partly motivated by altruism. I understand that you can't glean the meerkats motivations from its bark but nonetheless it would seem to me that running back to the hole before you even start barking would undermine a conclusion that suggests its motives were altruistic. As for C, is the correct interpretation that the bark could just be because the meerkat was scared and the alert is incidental? Why is A not correct? The line of thinking that would lead someone to C would not and likely never will occur to me. I instead need to find out why I should've ruled out A.