The occurrence which most likely would have no effect on 2017 net income (if all amounts involved are material) is the

sale in 2017 of an office building contributed by a stockholder in 1986.

collection in 2017 of a receivable from a customer whose account was written off in 2016 by a charge to the allowance account.

settlement based on litigation in 2017 of previously unrecognized damages from a serious accident that occurred in 2015.

Selling of fully depreciated equipment for its salavage (book) value.