13. Four brothers have different heights. Tobias is shorter than Victor by the same amount by which he is taller than Peter. Oscar is shorter than Peter by the same amount as well. Tobias is $184 \mathrm{~cm}$ tall and the average height of all the four brothers is $178 \mathrm{~cm}$. How tall is Oscar?
A $160 \mathrm{~cm}$
B $166 \mathrm{~cm}$
C $172 \mathrm{~cm}$
D $184 \mathrm{~cm}$
E $190 \mathrm{~cm}$