Considering Social Identity Theory,the Theory of Planned Behavior,and Research That

Considering Social Identity Theory,the Theory of Planned Behavior,and research that integrates them,when would farmers' own injunctive in-group norms be most useful in persuading them to use more sustainable agricultural practices ?

A) when farmers identify highly with city dwellers
B) when farmers identify highly other farmers
C) when farmers identify with the importance of protecting the environment
D) when farmers do not identify highly with city dwellers