Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Brian Johnson is a senior manager at Star Asset Management (SAMN), a large asset management firm in the United States. Tim Martin has just earned his advanced degree in statistics and was hired to support the trading team at SAMN. Martin meets with Johnson to undergo a training relating to SAMN's trading activities.Johnson begins the training with a review of the limit order book for Light Systems, Inc., which is presented in Exhibit 1. Three dealers make market for the shares of Light Systems. Based on these prices, SAMN's trading desk executes a market sell order for 1,100 shares of Light Systems.
| Exhibit 1Limit Order Book for Light Systems, Inc. |
| Bid | Ask |
| Dealer | TimeEntered | Price | Size | Dealer | TimeEntered | Price | Size |
| B | 10.10a.m. | $17.15 | 900 | C | 10.11a.m. | $17.19 | 1，200 |
| C | 10.11a.m. | $17.14 | 1，500 | B | 10.10a.m. | $17.20 | 800 |
| A | 10.11a.m. | $17.12 | 1，100 | A | 10.12a.m. | $17.22 | 1，100 |


Johnson then discusses a market buy order for 5,000 shares of an illiquid stock. The order was filled in three trades, and details about the three trades are presented in Exhibit 2.
| Exhibit 2 | Buy Trade Order Details |
| Trade# | Time | Trade Price | Trade Size | Bid Price | Ask Price |
| 1 | 9.45a.m. | $25.20 | 1，200 | $25.17 | $25.20 |
| 2 | 9.55a.m. | $25.22 | 1，300 | $25.19 | $25.22 |
| 3 | 11.30a.m. | $25.27 | 2，500 | $25.22 | $25.26 |


Johnson explains to Martin that the number of venues trading the same instruments has proliferated in recent years, and trading in any given instrument has now been distributed across these multiple venues. As a result, the available liquidity on any one of those exchanges represents just a small portion of the aggregate liquidity for that security. As a result, SAMN has had to adapt its trading strategies, particularly for large trades.Johnson asks Martin about his views on how the introduction of electronic trading might have impacted SAMN. Martin tells Johnson:Statement 1 Once built, electronic trading systems are more efficient and cheaper to operate than floor-based trading systems.Statement 2 Electronic trading systems have attracted a lot of new buy-side traders, and the increased competition has resulted in narrower bid–ask spreads.Statement 3 The introduction of electronic markets has had a much greater impact on the trading of corporate and municipal bonds than on the trading of equities.Johnson tells Martin that communication speed is SAMN's current highest prior-ity. All of SAMN's competitors have increased their communication speeds in recent months, and Johnson says management wants SAMN to be faster than its competi-tors. SAMN's trading desk is located in a residential area far from downtown where the exchanges it works with are located. SAMN's trading team is relatively large with experienced investment professionals, and the firm recently invested in fast computers with the latest algorithms.At the end of the training, Johnson gives Martin his first assignment. The assign-ment is for Martin to use the vast amount of data that SAMN has collected to design a machine learning (ML) model using advanced statistical methods to characterize data structures and relations. Then he has to build a trading algorithm based on the same model. Since electronic trading has added systemic risk to the market, Johnson asks Martin to suggest ways to minimize the systemic risk introduced by his algorithm. Martin offers two suggestions:Suggestion 1 Perform extensive testing of the algorithm before its launch.Suggestion 2 Impose mandatory trading halts if prices change outside a threshold range.A month into the job, Johnson sends Martin to an investment conference focused on abusive trading practices. Based on what he learned at the conference, Martin recommends to Johnson that SAMN incorporate a new rule that news be validated before a trade triggered by news is executed.
Based on Exhibit 2, the average effective spread of the three trades is closest to:
Option A:$0.0333.
Option B:$0.0367.
Option C:$0.0400.

Answer: C