Correct Answer - Option 2 : Decoder
Concept:
A decoder is a multiple input and multiple output logic circuit which coverts coded inputs into coded outputs. There is one to one mapping from input code to output code words. A decoder which has n bit binary input code and a one activated output out of 2n output code is called binary decoder.
Explanation:
A device which converts BCD to seven segment display is called decoder. Seven segment displays are used to give a visual indication of output states of digital ICs. These outputs are in BCD form and not suitable for directly driving seven segment displays. For this reason, decoder are used.