Final answer:
Nico's drink at Inge's apartment cannot be determined confidently from the provided options. The closest match is a coffee-based drink, similar to a described Viennese specialty involving strong black coffee with whipped cream and separate sugar.
Step-by-step explanation:
In answering the question of what Nico drinks at Inge's apartment, it is important to pay attention to details that define the drink as a mixture. None of the options listed directly correspond to the information provided, which describes a Viennese specialty. This specialty is a strong black coffee served in a glass and is topped with whipped cream, with powdered sugar served separately. Since it is not a simple coffee but includes additional elements like whipped cream and sugar, it does not match any of the given choices exactly.
Without further context or details from the source material directly linking to the options provided, the correct answer cannot be determined confidently. However, among the options, a coffee-based drink (option a) seems the closest to the described Viennese specialty, as it involves coffee with additional components.