The phrase 'before mass communication and literacy' suggests a time when the means to disseminate information widely and the ability to read and write were not as prevalent as they are today. This context implies that the spread of ideas was more limited and slower, as there were fewer channels for communication and a smaller portion of the population could access written information. Option A correctly captures this implication by stating that ideas spread more slowly and were less accessible to the general population. Option B is incorrect because, while it might have been easier for a select few to control information, the phrase does not specifically address control but rather the accessibility and speed of idea dissemination. Option C is incorrect because literacy rates directly influence the spread of ideas, as literacy enables individuals to access and share written information. Option D is incorrect because the phrase specifically refers to a time before mass communication, indicating that it was not the primary driver of idea dissemination at that time.