Question

baltimore is one of many coastal cities that have installed hardening structures, such as seawalls and bulkheads, along their shorelines. while these structures protect against erosion and other hazards, many scientists have found that the structures are ecologically harmful. for instance, fabio bulleri and m.g. chapman showed that seawalls along the coast of italy reduced algal species diversity. however, rachel k. gittman et al. have noted that most of these studies have taken place over only one - year or less, which may be insufficient to capture the full range of hardening structures ecological effects.
8 mark for review
which choice best describes the function of the underlined portion in the text?
a it praises the methodology bulleri and chapman and other researchers relied on in their studies.
b it indicates that an explanation offered by bulleri and chapman has been replaced by a more plausible one.
c it argues for the need to research the benefits of installing shoreline - hardening structures.
d it identifies a common limitation of investigations into the ecological effects of shoreline hardening.

Explanation:

The under - lined portion mentions that most studies have taken place over only one year or less, suggesting that this time - frame may be insufficient to capture the full range of ecological effects of shoreline hardening structures. This points to a common limitation in investigations into the ecological effects of such structures.

Answer:

D. It identifies a common limitation of investigations into the ecological effects of shoreline hardening.