| GMDSS operators should learn which of the following propagation "rules of thumb"? |
| A) Longer distance = lower frequency, Shorter distance = higher frequency; Daytime = higher frequency, nighttime = lower frequency. |
| B) Longer distance = lower frequency, Shorter distance = lower frequency, Daytime = lower frequency, nighttime = higher frequency. |
| C) Longer distance = higher frequency, Shorter distance = lower frequency, Daytime = higher frequency, nighttime = lower frequency. |
| D) Longer distance = higher frequency, Shorter distance = higher frequency, Daytime = lower frequency, nighttime = higher frequency. |
