Sarinna, an instrumentation engineer, has been assigned a challenging task of designing a specialized device to sterilize medical equipment. Sarinna believes that hard work and perseverance will help her perform well and complete the design on time. Her belief turns out to be a factor of motivation for her. As a result, she completes the project by meeting all the requirements on time. In this context, Sarinna is motivated by $\_\_\_\_\_.$

a$.$

instrumentality

b$.$

expectancy

c$.$

reinforcement

d$.$

valence