Techniques are many literary devices such as assonance, alliteration, consonance, flashbacks, foreshadow, hyperbole, irony, metaphor, onomatopoeia, personification, simile, symbolism. Techniques, also known as rhetorical devices, use our senses to drive the story home. Suspense is usually caused by the uncertainty of the future which triggers anxiety or excitement. The question is asking what techniques the author used to cause suspense. Hope that helps.