Final answer:
The escape speed from the Martian moon of Phobos is likely 1 km/s, considering that it is much smaller than Earth's moon, which has an escape speed of 2.38 km/s.
Step-by-step explanation:
The question is asking for the escape speed from the Martian moon of Phobos. The escape speed is the initial speed needed to break free from the gravitational pull of a celestial body without further propulsion. While the question does not provide direct information about Phobos' escape velocity, we know that the escape velocity from Earth is 11.2 km/s and from the Moon is much smaller at 2.38 km/s. Given that Phobos is much smaller than both the Earth and its own moon, it can be inferred that the escape speed from Phobos is also relatively small.
Since the Martian moon Phobos is significantly smaller than our moon, and the escape velocity from our moon is only 2.38 km/s, the escape speed from Phobos would be even lower. Among the options given, which are (1) 1 km/s, (2) 2 km/s, (3) 3 km/s, and (4) 4 km/s, the correct answer would likely be 1 km/s, considering that Phobos' gravitational pull is weaker due to its smaller size and mass compared to our moon.