To calculate the mean height of the 10 children, follow these steps:

1. Sum of the Heights:

Add all the heights together:
\[
145 + 163 + 159 + 162 + 167 + 149 + 150 + 160 + 170 + 155
\]
\[
= 1,580
\]

2. Calculate the Mean:

Divide the total sum by the number of children:
\[
\text{Mean} = \frac{\text{Sum of Heights}}{\text{Number of Children}}
\]
\[
\text{Mean} = \frac{1,580}{10} = 158
\]


The mean height of the children is 158 cm.

The correct answer is B. 158 cm.