Whistleblowing is a morally ambiguous activity on a complex concatenation of grounds: it necessarily involves a betrayal of trust on behalf of a public interest which itself is on some occasions morally ambiguous; it indicts otherwise morally competent individuals and organizations

Based on the given choices above that will complete the definition of whisteblowing, the correct answer is that -- it necessarily involves a betrayal of trust on behalf of a public interest which itself is on some occasions morally ambiguous. It is because this act is a way of exposing an individual or groups of individual with their way of doing an activity that is considered to be illegal or unethical.