Answer: A) Information about a route should not be sent back in the direction from which the original update came Explanation: A split horizon will not advertise a route back to the same router it learned the route from.

Answer: B) 3.5% Explanation: Seawater or salt water is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of approximately 3.5% or 35 parts per thousand. This means that for every 1 litre (1000 mL) of seawater there are 35 grams of salts dissolved in it.   Hence, The average salinity of seawater is 3.5%.