C. the word Have shows you it is past tense but it does not end in ed so it is no a past participle.
I think it's a phrase because this sentence doesn't include a verb and clauses have verbs......so..........the answer is a phrase
Cause and effect pattern is used.
Explanation:
Climate change pressures will influence marine planktonic systems globally, and it is conceivable that harmful algal blooms may increase in frequency and severity.
These pressures will be manifest as alterations in temperature, stratification, light, ocean acidification, precipitation-induced nutrient inputs, and grazing, but absence of fundamental knowledge of the mechanisms driving harmful algal blooms frustrates most hope of forecasting their future prevalence.
There is expectation that harmful algal bloom (HAB) geographical domains should expand in some cases, as will seasonal windows of opportunity for harmful algal blooms at higher latitudes.
