Which word best describes something that is "ascendant"?

The word "ascendant" refers to something that is rising or increasing in power, influence, or position. Therefore, the best choice is one that captures the idea of upward movement or progression.

Choosing the option that describes it as "tending or directed upward" precisely aligns with the definition of "ascendant." It conveys the notion of upward motion or improvement in status, making it the ideal descriptor.

The other options pertain to different concepts: being "stubbornly unyielding" describes inflexibility; a "mixture of liquids" refers to a physical blend; while "lack of respect" relates to behavior or attitude. None of these options convey the upward movement or elevation needed to accurately capture the essence of "ascendant."