'Mouse over on annotation selector and click on "Reply to Annotation".'

def click_reply_annotation(self, problem):

    annotation_span_selector = '.annotatable-span[data-problem-id="{}"]'.format(problem)
    self.mouse_hover(self.browser.find_element_by_css_selector(annotation_span_selector))
    self.wait_for_element_visibility(annotation_span_selector, 'Reply    to    Annotation    link    is    visible')
    annotation_reply_selector = '.annotatable-reply[data-problem-id="{}"]'.format(problem)
    self.q(css=annotation_reply_selector).click()
    self.active_problem = problem
