Explanation:

Meaning of "turn up":
"Turn up" is a phrasal verb that has multiple meanings depending on the context. In this case, it means to arrive or appear, especially unexpectedly or without prior notice.

Explanation of the options:
a) Land up: This phrase means to arrive or end up in a particular place or situation. It is similar to "turn up" in terms of meaning, but it is not the correct answer in this context.
b) Show up: This phrase means to arrive or appear, especially after being expected or invited. It is the correct answer in this context because it has the same meaning as "turn up."
c) Crop up: This phrase means to appear or occur suddenly or unexpectedly. It is similar to "turn up" in terms of meaning, but it is not the correct answer in this context.
d) Come up: This phrase means to approach or move towards someone or something. It is not the correct answer in this context because it does not convey the same meaning as "turn up."

Conclusion:
The correct answer is option 'B' - "show up." It is the most appropriate phrasal verb that conveys the meaning of "turn up" in the given context, which is to arrive or appear, especially unexpectedly or without prior notice.