Final answer:
The violation is Jonelli giving Anderb higher prices for personal sales.
Step-by-step explanation:
The most likely violation of the Code and Standards is option 3) Jonelli giving Anderb higher prices for personal sales.
According to the information given, Anderb has been receiving preferential treatment from Jonelli, where she is given lower prices for personal purchases and higher prices for personal sales compared to the prices given to Anderb's portfolio accounts and other investors. This conduct is a violation of the principle of fair dealing and loyalty to clients, which requires investment professionals to treat all clients fairly and not prioritize their personal interests.
Anderb's exclusive use of Jonelli for brokerage transactions (option 1) may raise concerns about potential conflicts of interest, but it is not explicitly mentioned as a violation in the given information. Filing monthly reports only for months with no personal transactions (option 4) may demonstrate a lack of transparency, but it is not a violation in itself.