DETAILS Write the number of the paragraph$($s$)$ where the author $...$

a$.$ describes the two features of typical design nudges.

b$.$ discusses some examples of design nudges in schools.

c$.$ explains how a design nudge improved safety in a city.

d$.$ introduces the idea that nudges can be bad for people.

e$.$ mentions nudges that may affect the foods people choose.

f$.$ refers to a nudge that might change how shoppers act.