I am unhappy because _____________________ some news recently.

The correct completion of the sentence is "I am unhappy because I have not received some news recently." This phrase effectively conveys the speaker's ongoing state of unhappiness linked to the lack of news.

The use of "have not received" highlights the present perfect tense, which is appropriate here because it indicates a connection between the past and the present. The news was expected in the past but has not arrived, leaving the speaker in their current state of dissatisfaction.

The other options, while they might seem plausible at a glance, do not quite fit as well in this context. For instance, using "have received" suggests the opposite of being unhappy, since receiving news typically contributes to a sense of resolution or closure. "Did not receive" focuses on a specific past event and does not convey the ongoing effect that this absence of news has on the speaker's current feelings. Meanwhile, "am waiting for" implies anticipation rather than disappointment, which shifts the emotional context away from being unhappy.

Thus, "have not received" perfectly captures the ongoing impact of the situation on the speaker's emotions.