Which of the following best describes the focus of the study "Hall & Wismar 2011: Habitat Factors Affecting Sockeye Salmon Redd Site Selection in Off-Channel Ponds of a River Floodplain"?

a) The impact of climate change on river ecosystems
b) Factors influencing the choice of nesting sites for sockeye salmon
c) Human activities affecting water quality in river floodplains
d) The effect of pollution on fish populations in off-channel ponds