Which of these refer to emphasis on a single musical note?
- syncopation
-tempo
-accent
-upbeat

accent

Explanation:

A pure and simple succession of heartbeats does not yet seem sufficient to set a rhythm.

This is where the first essentially musical rhythmic factor intervenes: the accents.

In the sound of the alarm clock, it is easy to see that the tics are a bit more pronounced than the taps.

Thus, instead of a simple succession of equal pulsations, we actually have a series of pulses of the same duration, but grouped two by two, the first one always a little stronger, accentuated:

These accents, the tics of our example, give an elementary principle of order to the succession of times: the groupings of two pulsations, one strong, the other weak.

i believe the answer is: a.  abstract forms were often used to represent human figures.

representing human figures in abstract forms is often used in the geometric period, not hellenistic  period.   during the hellenistic  period,   aesthetic value derived from creating arts which mimic the actual shape of a certain object or individuals.

hope this ! < 3

lithograph is created by etching the flat surface of a print.