"responsive" in the adjective sense
1. responsive, antiphonal
containing or using responses alternating
readily reacting or replying to people or events or stimuli showing emotion
"children are often the quickest and most responsive members of the audience"
3. reactive, responsive
reacting to a stimulus
"the skin of old persons is less reactive than that of younger persons"
Source: WordNet® (An amazing lexical database of English)
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