Who belongs to the Group, Brain Test

Today Briquinex takes you on a trip and as usual comes with a test. You are told that:
Among the children K, L, M and adults S, T shall be elected a group of three tourists. In addition we know that:

photo source: wikipedia

• a) K and S are the only male; 
• b) K does not go on the trip if he is the only child in the group; 
• c) M does not go on the trip with male persons. 

If K belongs to the group, Briquinex wants you to find out who will be the other two tourists?