B is organised on Tuesday. Now, D is followed by the day with nno lecture. D cannot be organised on Friday because then E will be on Tuesday (there is a gap of two days between D and E). It cannot be organised on Thursday (because then, there will be no lecture Friday). B cannot be followed by D. So, D will be organised on Sunday and E on Wednesday. No lecture will be organised on Monday. A cannot be organised on Thursday. So, A will be organised on Saturday. F and C will be organised on Thursday and Friday respectively.

So the correct order is :

Sunday |
Monday |
Tuesday |
Wednesday |
Thursday |
Friday |
Saturday |

D |
x |
B |
E |
F |
C |
A |

So, **A is the last lecture.**