Final answer:
Cohesion in writing refers to how ideas connect with each other and flow logically. Transitional words and phrases help achieve cohesion by signaling the connections between sentences and paragraphs.
Step-by-step explanation:
In writing, cohesion refers to how ideas connect with each other and flow logically.
When ideas have cohesion, they are not loosely connected or unrelated (option a), repetitive and redundant (option c), or presented in a random order (option d).
Rather, ideas that have cohesion flow logically from one to the next (option b), making the writing easy to follow and understand.
Transitional words and phrases play a crucial role in achieving cohesion, as they signal the connections between sentences and paragraphs.