In what way can "avail" be understood?

"Avail" is primarily understood as a verb meaning to help or assist in achieving a particular outcome or success. It conveys the idea of making oneself useful or taking advantage of something for a beneficial purpose. When someone states they avail themselves of a service or an opportunity, it means they are making use of that service or opportunity to their advantage, thus enhancing their chances of success. This context aligns perfectly with the choice that suggests aiding or helping to succeed.

The other options introduce meanings that do not align with the core definition of "avail." For instance, abandoning or neglecting implies a lack of support or assistance, which directly contradicts the intention behind availing oneself. Similarly, hindering or obstructing, as well as complicating matters, suggests actions that are counterproductive and do not resonate with the supportive connotation of "avail."