Questões de Concurso Militar ESCOLA NAVAL 2010 para Aspirante - 2º Dia

Which alternative below is NOT CORRECT, based on the text?

The relative pronoun "which" in " (...) large stretches of which are favorite nesting spots for turtles." refers to:

Which is the correct option to complete the text below?
Water shortages don't just affect ______ (1). _____ (2) can also
seriously harm ______ (3) environment. ________ (4) water comes from
rivers and groundwater so every drop ________ (5) use has a direct
effect on the _________ (6) environment.
(Adapted from: http: / /www.environment-agency.gov.uk)